Caracterização estrutural, funcional e diversidade de osmoprotetores no transcriptoma de Stylosanthes scabra (Vogel) sob déficit hídrico

Abstract

Abiotic stress conditions like water deficit affect plant growth causing morphological, physiological, biochemical and molecular changes, changing genes expression that activate biochemical and physiological responses, such as compatible solutes accumulation. Osmoprotectants are highly soluble compounds that act primarily on cellular osmotic adjustment maintaining their turgidity (cell volume) even with low water potential. Molecular and computational approaches have made possible new perspectives on the structure and function of proteins and genes already known and have proven efficient in studies with known genome species, however, few studies have been conducted with native species. Stylosanthes scabra, a legume with high forage potencial, it is Brazilian semiarid native specie and has drought tolerance. The present work aimed to identify and characterize transcripts belonging to different classes of osmoprotectants in S. scabra transcriptome of under water deficit as well as validate its expression in RT-qPCR. Initially, candidate sequences for osmoprotectants genes were obtained from S. scabra database proceeding with data annotation, translation and identification of conserved domains through in silico methods. A total of 74 osmoprotectants sequences with conserved domains were identified for S. scabra: 40 of Trehalose (TPS and TPP), 17 of Myo inositol (MIPS and IMP), 10 of Glycine betaine (BADH and CMO) and 7 of Proline (P5CS and P5CR) equivalent results described in other plants. These were anchored in the A. duranensis genome (n = 10) revealing a total of 19 anchored loci similar to the results that has been found in soybean, another Fabaceae specie. Phenetic orthologous trees of osmoprotectants genes demonstrated the clustering of S. scabra sequences with other Fabaceae species, proving their similarity and pointing out to these protein conservation. The in silico differential gene expression analysis was performed using RNA seq data, where the 35 transcripts were differentially expressed, presenting induction and repression in both 6 h and 24 h stress periods showing that these genes participate in S. scabra water deficit response. These results prove to be valuable for genetic breeding of S. scabra and other legumes of agricultural importance.